1. Field of the Invention
The present invention relates to a recording tape cartridge accommodating, within a case, a single reel on which is wound a recording tape such as a magnetic tape or the like, the magnetic tape or the like being used as a recording/playback medium mainly of computers or the like.
2. Description of the Related Art
Conventionally, magnetic tape cartridges have been known in which a magnetic tape, which is used as a data recording/playback medium of a computer or the like, is wound on a single reel, and the reel is accommodated in a case. A leader member, such as a leader pin, a leader tape, or a leader block, is provided at the distal end of the magnetic tape. A pull-out means provided at a drive device pulls the leader member out from an opening of the magnetic tape cartridge, and winds the magnetic tape, which is fixed to the leader member, onto a take-up reel of the drive device.
A reel gear is formed in an annular form in the center of the bottom surface of a reel which emerges from an open hole formed in the bottom surface of the magnetic tape cartridge. Due to a driving gear, which is provided at a rotating shaft of the drive device, meshing with this reel gear, the reel is driven to rotate. By rotating the reel of the magnetic tape cartridge and the take-up reel of the drive device synchronously, data can be recorded onto the magnetic tape, and data recorded on the magnetic tape can be played back.
Such a magnetic tape cartridge requires little space for storage, and a large amount of information can be recorded thereon.
The position of the opening and the type of the door which opens and closes the opening differ for each type of leader member. For example, in the case of a leader pin, as shown in FIG. 6, an opening 68 for pulling out of a leader pin 60 is formed at the front end of a side wall 64 of a case 62. The opening 68 is opened and closed by a door 66 which slides in the direction of loading the magnetic tape cartridge into a drive device (the direction of arrow P) and the direction opposite thereto.
A reel 72 on which a magnetic tape T is wound is rotatably accommodated in the case 62, and the leader pin 60 is attached to the distal end of the magnetic tape T. A pair of upper and lower pin holding portions 70, which hold the leader pin 60 when the magnetic tape cartridge is not being used (is being stored or the like), are provided at the inner side of the opening 68 of the case 62. The pin holding portions 70 are concave portions which are substantially semicircular as seen in plan view, and respective one portions of the pin holding portions 70 are open so that the leader pin 60 can enter therein and exit therefrom. Both end portions 60A of the leader pin 60, which is in a state of standing upright, are inserted into these concave portions (the pin holding portions 70).
However, when the opening 68 is formed at the front end portion of the side wall 64 of the case 62 in this way, the right end portion of a front wall 63 is a free end due to the formation of the opening 68. Thus, the strength of the front wall 63 itself is relatively weak. Therefore, when the front wall 63 receives the impact of a drop, problems arise such as the leader pin 60 held at the inner side of the opening 68 falls out from the pin holding portions 70, or the position of the leader pin 60 becomes offset. Namely, the front wall 63 is the portion which is most easily damaged by the impact of a drop. Ensuring the strength of this portion has conventionally been a task to be achieved.